Guess the correlation. Measurements in large samples show that the correlation

(a) between SAT scores and college GPA is about .

(b) between the IQ and the GPA of seventh-grade students is about .

(c) between the GPA of a student and the average GPA of his or her roommates is about .

The answers (in scrambled order) are r = 0.2 r = 0.5 r = 0.8 Match the answers to the statements and explain your choice.